1. Field
This invention relates to data input devices, and more particularly, to a master controller which may be used for directing movements of a robot and which is particularly useful for robotically enhanced surgery.
2. Background
In robotically assisted surgery, the surgeon typically operates a master controller to remotely control the motion of surgical instruments at the surgical site. The master controller may be separated from the patient by a significant distance (e.g., across the operating room, in a different room, or in a completely different building than the patient). Alternatively, a master controller may be positioned quite near the patient in the operating room. Regardless, the master controller will typically include one or more hand input devices.
These hand input devices are coupled by a servo mechanism to the surgical instrument. More specifically, servo motors move a manipulator or “slave” supporting the surgical instrument based on the surgeon's manipulation of the hand input devices. During an operation, the surgeon may employ, via the robotic surgery system, a variety of surgical instruments such as tissue graspers, needle drivers, electrosurgical cautery probes, etc. Each of these structures performs functions for the surgeon, for example, holding or driving a needle, grasping a blood vessel, or dissecting, cauterizing, or coagulating tissue.
To deliver the full potential of this new form of surgery, the robotic system will preferably allow movement of the surgical end effector in both position and orientation. Directing such robotic input is much easier when the surgeon is able to move the hand input device with motions that correspond to the desired motions of the end effector. In particular, it is desirable to maintain a substantial correspondence between the orientation of the hand input device and the end effector.
One obstacle to maintaining a substantial correspondence between the orientation of the hand input device and the surgical end effector is the need to reposition elements of the robotic surgical system during surgery. For example, it may be necessary to reposition an endoscopic camera to gain a better view of the surgical field. Repositioning the camera will change the perceived orientation of the surgical end effector and thus end the substantial correspondence between the orientation of the hand input device and the end effector as seen by the surgeon in a visual display at the master controller.
Existing robotic surgical systems may provide a first mode in which the hand input device controls the surgical end effector and a second mode that allows elements to be repositioned. The orientation of the hand input device may be adjusted when changing from the second mode to the first mode to restore the substantial correspondence between the orientation of the hand input device and the end effector. While this is effective, adjusting the orientation of the hand input device may take a significant amount of time because it is undesirable to move the hand input device abruptly. In many surgical procedures it is desirable to reposition elements of the robotic surgical system fairly frequently. Thus adjusting the orientation of the hand input device may consume a substantial amount of time and disrupt the progress of the surgical procedure.
In light of the above, it would be desirable to provide an improved apparatus and method for orienting an operator input device for a robotic surgical system when elements of the system are repositioned.